Mallet drive fastener driving machine

ABSTRACT

A mallet drive stapling machine is shown which includes a housing, a magazine, a piston raceway and a drive channel within the housing. A follower is movable within the magazine to sequentially propel fasteners contained therewithin into operative relationship with the drive channel. A piston having an enlarged upper portion, an outwardly projecting intermediate portion, and a lower portion is movable within the piston raceway. A driver blade is secured to the lower portion of the piston and is selectively movable within the drive channel to drive fasteners contained therein into work. The lower portion of the piston is substantially circular and between the lower portion and the enlarged upper portion is an intermediate portion which is formed with four projecting portions, each two of these portions are oppositely extending with respect to one another and each pair of said oppositely extending portions are perpendicular with respect to one another. A coil spring is retained within said piston raceway and surrounds the piston, with the piston raceway having an inwardly extending portion to retain the spring. A resilient bumper is selectively abuttable with the base portion of the piston when the piston is moved downwardly.

United States Patent [72] Inventor Richard A. Kuhlman Forest Park, Ill. [21 App]. No. 853,625 [22] Filed Aug. 26, 1969 [45] Patented Oct. 12, 1971 [73] Assignee Spotnails, Inc.

Long Island City, N.Y.

[54] MALLET DRIVE FASTENER DRIVING MACHINE 2 Claims, 4 Drawing Figs.

[52] [1.8. CI 227/120 [51] B25c 1/00 [50] 227/ l 20, 121, 126, 127,129, 147, 132

[5 6] References Cited UNITED STATES PATENTS 406,075 7/1889 White 227/121 2,580,065 12/1951 Anstett 227/129 X 2,931,040 4/1960 Lawler 227/132 Primary Examiner-Granville Y. Custer, Jr. Attorney-I. Walton Bader ABSTRACT: A mallet drive stapling machine is shown which includes a housing, a magazine, a piston raceway and a drive channel within the housing. A follower is movable within the magazine to sequentially propel fasteners contained therewithin into operative relationship with the drive channel. A piston having an enlarged upper portion, an outwardly projecting intermediate portion, and a lower portion is movable within the piston raceway. A driver blade is secured to the lower portion of the piston and is. selectively movable within the drive channel to drive fasteners contained therein into work. The lower portion of the piston is substantially circular and between the lower portion and the enlarged upper portion is an intermediate portion which is formed with four projecting portions, each two of these portions are oppositely extending with respect to one another and each pair of said oppositely extending portions are perpendicular with respect to one another.

A coil spring is retained within said piston raceway and surrounds the piston, with the piston raceway having an inwardly extending portion to retain the spring. A resilient bumper is selectively abuttable with the base portion of the piston when the piston is moved downwardly.

PATENTED [JET 1 2 I97] SHEET 10F 2 MALLET DRIVE FASTENER DRIVING MACHINE DESCRIPTION OF THE INVENTION This invention relates to a Mallet Drive Fastener Driving Machine which is used to drive various types of fasteners, such as staples, nails and the like, into various types of work.

In various operations such as the nailing of floors, installation of linoleum, installing lead wires for telephones, television antennaes, radio applications and the like, and various other applications of similar type where a fastener is to be driven into work at various sequential points and where the type of operation or cost factors militate against the use of power driven tools but where conventional hand-nailing or fastening is impractical, a tool of this type finds utilization.

Such mallet drive machines, generally, include a downwardly movable piston which is actuated by the blow of a mallet, a driver blade operatively connected to the piston, a bumper abuttable with the piston at the end of the driving stroke and a magazine within which the fasteners are contained in laterally aligned relationship. Follower means are provided within the magazine to sequentially propel the leading fastener into abutting relationship with the driver blade.

Conventional Mallet Drive Fastener Driving machines have been relatively costly to manufacture and, as a result, these machines have only been available to professionals" who could afford the cost of purchasing one of these devices. The price charged for prior devices was completely beyond the reach of a do it yourselfer, his wife, or a similar amateur workman.

I have produced a Mallet Drive Fastener Driving Machine which is a relatively inexpensive tool and is well within the budget capabilities of users of the latter type.

The construction of the tool, while rugged, is quite inexpensive. Plastic molded parts are extensively used in the device and the construction is such that the number of parts to be assembled to produce the completed machine is kept to a minimum.

The construction of the tool of this invention is likewise simple and rugged so that the possibility of failure of parts is kept to a minimum.

In brief, the Mallet Drive Fastener Driving Machine of this invention includes a housing which is preferably made of moldable plastic and preferably in two separate sections which are secured to one another by screws or similar fasteners. A magazine is included within the housing to contain a plurality of fasteners such as staples and nails in laterally aligned relationship. A follower is forwardly biased within the magazine and is adapted to propel the leading fastener into driving relationship. A piston raceway is provided within the magazine within which a piston is disposed, a driver blade is operatively connected to the piston and is adapted to abut the leading fastener and to drive it into work, and spring means are operatively connected with the piston in order to return the piston to its normal position.

The above sets forth a brief description of this invention and the principal objects and advantages thereof. Other objects and advantages of this invention will become apparent to the reader of this specification as this description proceeds.

The invention will be further described by reference to the accompanying drawings which are made a part of this specification.

FIG. 1 is a side elevational view of a Fastener Driving Machine made in accordance with this invention.

FIG. 2 is a rear elevational view of the form of invention shown in FIG. 1.

FIG. 3 is a cross-sectional view taken along lines 3-3 of FIG. 2.

FIG. 4 is a cross-sectional view taken along lines 4-4 of FIG. 1.

The invention will now be further described by reference to the specific form thereof as shown in the accompanying drawings. In this connection, however, the reader is cautioned to note that such specific form of this invention is merely for illustrative purposes and for purposes of example only. Various changes and modifications could obviously be made within the spirit and scope of this invention.

Now referring to the specific form of this invention as shown in the accompanying drawings, the Fastener Driving Machine of this invention is formed with a housing 12 which is preferably made of an impact-resistant plastic such as high-impact styrene, polycarbonate resin or the like. Housing 12 is formed of a pair of complementary sections 13 and 14 which are held together by screws 15. Within housing 12 is a magazine 16 having a rail 17 therewithin. A follower 18 is operatively connected with rail 17 and is secured to rod 19 through a pair of upstanding portions 38 which are provided with recesses 39. Rod 19 is offset at its rear portion 21 and the offset rear portion is disposable within a recess 22 which is cut out of magazine 16. A spring 20 is retained between one of the offset portions 38 of follower 18 and the offset portion 21 of rod 19.

A plurality of fasteners 23 such as nails, staples or the like, is operatively connected to rail 17. Follower l8 normally urges fastener strip 23 forwardly so that the leading fastener 24 of the strip is disposed within drive channel 25 provided within housing 12.

Housing 12 is also provided with a handgrip recess 40 therewithin.

A piston raceway 28 is also provided within housing 12 and a piston 29 is disposable within this raceway. Piston raceway 12 is formed with a narrow upper portion 41, a widened intermediate portion 42 and a narrow lower portion 43. Piston 29 bears an enlarged top portion 32, a substantially cylindrical lower portion 31 and an intermediate portion 37. A plurality of projecting guide portions 44 and 45 are also provided. The opposite members of portions 44 and of portions 45 are vertically aligned with one another and are oppositely extending while portions 44 and 45 are perpendicular to one another. This permits a substantial reduction of the frictional force between the piston and the piston raceway as will be subsequently explained.

Piston 29 also bears an enlarged portion 36 which is carried by intermediate portion 37 and which acts as a stop limiting the upward travel of the piston. An inwardly projecting retainer 35 is likewise provided within the intermediate portion 42 of the piston raceway. A spring 30 is likewise provided which, in the preferred modification, is a coil spring and is retained between elements 35 and 36.

A bumper 26 is likewise provided below portion 43 of piston raceway 28. Bumper 26 is retained above drive channel support member 47 which also defines drive channel 25. A plastic member 48 preferably made of polycarbonate resin is disposed above bumper 26 and serves to transmit the piston impact to bumper 26. Bumper 26 is, of course, made of a resilient material such as natural or synthetic rubber.

A driver blade 27 is secured to piston 29 by means of pin 34 which is disposed within recess 33 provided in piston 29. A tongue 46 may optionally be provided in order to improve the securing of driver blade 27 to piston 29. Piston 29 is likewise made of plastic such as polycarbonate or high-impact styrene.

With the above description, the operation of this invention can now be explained.

In the factory, the fastener driving machine is assembled by placing the internal components within one side of housing 12 and the opposite side of housing 12 is then secured into place. The fastener strip 23 is then placed in operative relationship with rail 17 and follower 18 with its attached rod 19 put in position behind strip 23. The rear portion 21 of rod 19 is then secured into position within recess 22 so that spring 20 normally will urge follower l8 forwardly. The machine is then aligned in juxtaposition with work so that drive channel 25 is aligned with the portion of the work in which the lead fastener 24 is to be driven. It is noted that, in this position, piston 32 is urged upwardly by coil spring 30 and is retained in its most upward position by portion 36.

Portion 32 of piston 29 is then given a smart blow with a mallet. This blow drives piston 29 downwardly against tension of spring 30 and moves drive blade 27 into drive channel 25 and against the leading fastener 24, thereby driving the fastener 24 into the work. The lower portion of piston 29 will eventually abut plastic member 48 which overlies bumper 26 and will tend to deform this plastic member and in turn deform bumper 26. Bumper 26 will transmit the shock to the support 47 which defines drive channel 25 and this shock will be dissipated, to a great degree by the offset portions 49 of member 47.

When the downward force is no longer present against piston 29, the spring 30 will return the piston to the normal position shown in FIG. 3. This will remove driver blade 27 from drive channel 25 and will thus permit follower 18 to position the next leading fastener 24 into drive channel 25 so that the process can be repeated.

It is noted that piston 29 is movable within piston raceway 28. It is noted that piston 29 abuts piston raceway 28 only where projecting portions 44 and 45 are present. As a result, the frictional force between portions 44 and 45 and piston raceway 28 is considerably reduced over what these forces would be if piston 29 would be of the conventional rounded configuration and would abut piston raceway 28 around its entire perimeter.

The foregoing sets forth the manner in which the objects of this invention are achieved.

lclaim: a

1. A mallet driven fastener driving machine comprising, in combination, a housing having a magazine, a piston raceway, and a drive channel therewithin, said piston raceway having a pair of spaced inturned portions therewithin, a follower within said magazine adapted to sequentially propel fasteners into operative relationship with said drive channel, a piston reciprocatingly movable within said piston raceway formed with a plurality of outwardly extending lateral flutes, an upper portion adapted to be selectively struck by a mallet, and an enlarged laterally projecting stop portion beneath said flutes, said flutes having a total cross-sectional area substantially less than the total cross-sectional area of said piston, said stop portion being larger than said inturned portions of said piston raceway, said flutes being the sole portions of said piston abutting said piston raceway above said stop portions, and a coil spring disposed about said piston between said inturned portions biasing said piston into an upward position.

2. A mallet driven fastener driving machine as described in claim 1 said flutes being four in number, each two of said flutes being oppositely extending with respect to one another and each pair of oppositely extending portions being perpendicular to one another. 

1. A mallet driven fastener driving machine comprising, in combination, a housing having a magazine, a piston raceway, and a drive channel therewithin, said piston raceway having a pair of spaced inturned portions therewithin, a follower within said magazine adapted to sequentially propel fasteners into operative relationship with said drive channel, a piston reciprocatingly movable within said piston raceway formed with a plurality of outwardly extending lateral flutes, an upper portion adapted to be selectively struck by a mallet, and an enlarged laterally projecting stop portion beneath said flutes, said flutes having a total cross-sectional area substantially less than the total Cross-sectional area of said piston, said stop portion being larger than said inturned portions of said piston raceway, said flutes being the sole portions of said piston abutting said piston raceway above said stop portions, and a coil spring disposed about said piston between said inturned portions biasing said piston into an upward position.
 2. A mallet driven fastener driving machine as described in claim 1 said flutes being four in number, each two of said flutes being oppositely extending with respect to one another and each pair of oppositely extending portions being perpendicular to one another. 